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Atherosclerosis is a chronic inflammatory disease, the progression of which is associated with the increased expression of cell adhesion molecules on vascular smooth muscle cells (VSMCs). Lobastin is a new pseudodepsidone isolated from Stereocaulon alpinum, Antarctic lichen, which is known to have antioxidant and antibacterial activities. However, the nature of the biological effects of lobastin still remains unclear. In the present study, we examine the effect of lobastin on the expression of vascular cell adhesion molecules (VCAM-1) induced by TNF-α in the cultured mouse VSMC cell line, MOVAS-1. Pretreatment of VSMCs for 2 h with lobastin (0.1-10 μg/ml) concentration-dependently inhibited TNF-α-induced protein expression of VCAM-1. Lobastin also inhibited TNF-α-induced production of intracellular reactive oxygen species (ROS). Lobastin abrogated TNF-α-induced phosphorylation of p38 and ERK 1/2, but not JNK, and also inhibited TNF-α-induced NK-κB activation. In addition, lobastin suppressed TNF-α-induced IκB kinase activation, subsequent degradation of IκBα and nuclear translocation of p65 NF-κB. Our results indicate that lobastin downregulates the TNF-α-mediated induction of VCAM-1 in VSMC by inhibiting the p38, ERK 1/2 and NF-κB signaling pathways and intracellular ROS generation. Thus, lobastin may be an important regulator of inflammation in the atherosclerotic lesion and a novel therapeutic drug for the treatment of atherosclerosis. [ABSTRACT FROM AUTHOR]

The sulfated exopolysaccharide p-KG03, which is produced by the marine microalga Gyrodinium impudicum strain KG03, exhibited impressive antiviral activity in vitro (EC50 = 26.9 µg/ml) against the encephalomyocarditis virus (EMCV). Depending on the p-KG03 concentration, the development of cytopathic effects in EMCV-infected HeLa cells was either inhibited completely or slowed. Moreover, p-KG03 did not show any cytotoxic effects on HeLa cells, even at concentrations up to 1000 µg/ml. The polysaccharide was purified by repeated precipitation in ethanol, followed by gel filtration. The p-KG03 polysaccharide had a molecular weight of 1.87 × 107, and was characterized as a homopolysaccharide of galactose with uronic acid (2.96% wt/wt) and sulfate groups (10.32% wt/wt). The biological activities of p-KG03 suggest that sulfated metabolites from marine organisms are a rich source of antiviral agents. This is the first reported marine source of antiviral sulfated polysaccharides against EMCV. The p-KG03 polysaccharide may be useful in the development of marine bioactive exopolysaccharide for biotechnological and pharmaceutical products. [ABSTRACT FROM AUTHOR]

Of a number of actinomycetes isolated from Antarctica and coastal regions of Korea, one isolate, identified as a Streptomyces sp., demulsified an emulsion of kerosene/0.2% Triton X-100 (2:1, v/v) within 1 min. The aerial spores broke emulsions of low viscosity hydrocarbons such as kerosene and gasoline within 1 min, but after 3 min of contact they could demulsify less than 50% of emulsions of high viscosity hydrocarbons diluted with kerosene. [ABSTRACT FROM AUTHOR]